Dengue vector control and community participation in Catanduva, São Paulo State, Brazil

This study aimed to identify changes in knowledge and practices learned to prevent dengue fever in two areas of Catanduva, S?o Paulo State, from 1999 to 2001: a study area and a control area. The study included an initial quantitative survey, qualitative research, a preliminary diagnosis presented to the community to launch a discussion aimed at defining future actions, implementation of the actions in the study area with community participation (but without changes in the control area), and a final comparison of the two areas. Changes in the study area included: vector control workers began demonstrating preventive measures without removing potential breeding places or using larvicide; use of educational aids specific to the local reality; activities related to the residents priorities; and activities such as music, theater skits, scavenger hunts, and games to demonstrate the vector cycle. Potential domiciliary breeding sites were significantly reduced; the proportion of houses without breeding sites was significantly increased; and there was an increase in the percentage of individuals who recognized the larval form of the vector in the study area as compared to the control area.     

Hand Washing Among School Children in Bogotá, Colombia

Objectives. We assessed hand-washing behaviors and intentions among school children in Bogotá, Colombia, to help identify and overcome barriers to proper hygiene practices.Methods. Data on hand-washing behavior and intentions and individual and contextual factors were collected from 2042 sixth- through eighth-grade students in 25 schools in Bogotá via anonymous questionnaires. A member of the school administration or teaching staff completed a questionnaire about the school environment. Site inspections of bathroom facilities were conducted.Results. Only 33.6% of the sample reported always or very often washing hands with soap and clean water before eating and after using the toilet. About 7% of students reported regular access to soap and clean water at school. A high level of perceived control was the strongest predictor of positive hand-washing intentions (adjusted odds ratio [AOR] = 6.0; 95% confidence interval [CI] = 4.8, 7.5). Students with proper hand-washing behavior were less likely to report previous-month gastrointestinal symptoms (OR = 0.8; 95% CI = 0.6, 0.9) or previous-year school absenteeism (OR = 0.7; 95% CI = 0.6, 0.9).Conclusions. Scarcity of adequate facilities in most schools in Bogotá prevents children from adopting proper hygienic behavior and thwarts health promotion efforts. The current renovation program of public schools in Bogotá provides a unique opportunity to meet the challenges of providing a supportive environment for adoption of healthy behaviors.Remarkable improvements have been made in the past century in the fight against communicable diseases, yet a significant amount of mortality and morbidity worldwide can still be attributed to these conditions.¹ Respiratory infections and diarrheal diseases—the 2 leading causes of disease burden globally—are responsible for half of all child deaths each year.¹ The burden of communicable disease remains predominantly acute in developing regions of the world,² and children remain particularly vulnerable.³Recent estimates in Colombia indicate that acute respiratory and intestinal infections are the main cause of mortality among children aged 1 to 4 years, the second leading cause of death among girls aged 5 to 14 years, and the third leading cause of infant mortality.⁴ According to a recent national household survey in Colombia, 14.1% and 9.6% of children younger than 5 years had experienced diarrhea or an acute respiratory infection, respectively, in the 2 weeks before the survey.⁴Despite much evidence supporting the effectiveness of measures such as vaccination,^5,6 improvement in sanitary conditions,^3,6 and basic hygiene practices^3–7 in controlling communicable diseases, many developing nations have yet to achieve effective vaccination coverage⁶ and remain plagued with poor sanitary conditions. Basic personal hygiene behaviors, such as hand washing, are still not widely practiced.⁷Diverse health behavior and social marketing theories have been applied in the design and implementation of behavioral change interventions that promote infection-control practices.^8,9 The theory of reasoned action and planned behavior,^10,11 for example, suggests that a person''s behavior is determined by her or his intention to perform the behavior. Intention, in turn, is a function of the person''s attitudes toward the behavior, beliefs concerning benefits or harms of adopting or not adopting the behavior, subjective norms and normative beliefs, and perceived control over the opportunities, resources, and skills necessary to perform the behavior.^9,10 More recently, ecological approaches have been incorporated into behavioral theories to disentangle independent effects of individual and contextual factors on health behavior.¹² The underlying premise of such models is a bidirectional relation between environmental modifications and behavioral change.^12,13Bearing in mind that school children have been consistently implicated in the spread of communicable diseases¹⁴ and that the school has been recognized as a vital setting for health promotion, we assessed the prevalence and individual and contextual determinants of proper hand-washing behavior and positive hand-washing intentions among school children in Bogotá, Colombia.     

Dengue epidemic in Fortaleza, Ceará: randomized seroepidemiologic survey

OBJECTIVE: A seroepidemiological random survey was carried out in Fortaleza city, State of Ceará, Brazil, following an epidemic of dengue virus type 2 (DEN 2), with the purpose of evaluating the frequency of clinical manifestations (signs and symptoms) and the prevalence of dengue infection. METHOD: A questionnaire calling for information on address, sex, age, clinical, epidemiological and economic status was applied to the population, followed by venupuncture collection of 5-10 ml of blood for testing by hemagglutination-inhibition (HI). The sample was calculated to obtain a prevalence of 20% with relative risk of 10% and confidence interval of 95%. All information obtained was analyzed by computer using Epi Info 5.0, Lotus 123, Excel 5.0, and Stata software. RESULTS AND CONCLUSIONS: A total of 1,341 serum samples were obtained from nine Health Districts (SD) and tested by hemagglutination inhibition. Of these, 589 (44%) were positive and 752 (56%) negative. Of the positive results, 93 primary responses (PR) (7%) to DEN-2 and 496 secondary responses (SR) (37%) were observed. The global prevalence in the SD ranged from 21% to 71%. There were 41% (243/589) asymptomatic infections and 59% (346/589) symptomatic infections. Data analysis showed no difference in frequency by sex, age, on schooling, although a highly statistically significant difference was found as between the different social classes, the infection most commonly observed being among people of better social status. The stratification of positive cases showed greater prevalence of AI (p < 0.001) and SI (p < 0.0001) in both sexes, among people with SR rather than PR. The most prevalent symptoms were fever, headache, muscle pains, rash, dizziness, and joint pains. Moreover, itching, retro-bulbar pain, rash, and gingival bleeding, showed statistically significant differences. On the other hand, dizziness and joint pains were more associated in the patients with SR than PR, and statistically significant differences were also observed.     

National dengue surveillance in Cambodia 1980�C2008: epidemiological and virological trends and the impact of vector control

Objective

Dengue has been reportable in Cambodia since 1980. Virological surveillance began in 2000 and sentinel surveillance was established at six hospitals in 2001. Currently, national surveillance comprises passive and active data collection and reporting on hospitalized children aged 0–15 years. This report summarizes surveillance data collected since 1980.

Methods

Crude data for 1980–2001 are presented, while data from 2002–2008 are used to describe disease trends and the effect of vector control interventions. Trends in dengue incidence were analysed using the Prais–Winsten generalized linear regression model for time series.

Findings

During 1980–2001, epidemics occurred in cycles of 3–4 years, with the cycles subsequently becoming less prominent. For 2002–2008 data, linear regression analysis detected no significant trend in the annual reported age-adjusted incidence of dengue (incidence range: 0.7–3.0 per 1000 population). The incidence declined in 2.7% of the 185 districts studied, was unchanged in 86.2% and increased in 9.6%. The age-specific incidence was highest in infants aged < 1 year and children aged 4–6 years. The incidence was higher during rainy seasons. All four dengue virus (DENV) serotypes were permanently in circulation, though the predominant serotype has alternated between DENV-3 and DENV-2 since 2000. Although larvicide has been distributed in 94 districts since 2002, logistic regression analysis showed no association between the intervention and dengue incidence.

Conclusion

The dengue burden remained high among young children in Cambodia, which reflects intense transmission. The national vector control programme appeared to have little impact on disease incidence.     

Population-based surveillance for invasive pneumococcal disease and pneumonia in infants and young children in Bogotá, Colombia

Background

In children <5 years of age, Streptococcus pneumoniae (SP) is, globally, the leading cause of vaccine-preventable death. Surveillance conducted in Bogotá, Colombia estimated incidence rates of invasive pneumococcal disease (IPD), clinical and chest radiograph-confirmed pneumonia (CXR+Pn); SP serotype distribution and antimicrobial susceptibility.

Methods

This prospective population-based surveillance was conducted from 2006 to 2008 in children 28 days to <36 months of age seeking care at SaludCoop centers. We determined incidence rates of IPD and pneumonia (clinical and CXR+Pn). Eligibility criteria included: temperature ≥39.0 °C within 24 h and/or clinical suspicion of IPD or pneumonia. Blood was obtained for culture in all children. Other sterile site specimens were obtained per routine practice.

Results

Of 8261 subjects enrolled, a total of 64 had invasive pneumococcal disease detected by isolation of SP from nonduplicative cultures (62) or detected solely by PCR and a clinical picture consistent with IPD (2). The overall IPD incidence rates for culture-positive only cases for children aged 28 days to <36 months was 76.4/100,000 per year for years 1 and 2 combined. Age stratification found the highest rates in children 6–12 and 12 to <24 months of age. IPD incidence rates were assessed for bacteremic pneumonia (54.2/100,000), bacteremia (17.2/100,000), meningitis (3.7/100,000), and sepsis (1.2/100,000). Most common serotypes causing IPD were: 14 (51.6%), 6B (9.7%), and 19F (9.7%). Coverage of IPD cases by pneumococcal conjugate vaccine (PCV) 7, PCV10, and PCV13 was 77.4%, 85.5%, and 91.9%, respectively. Twenty-eight isolates (45.2%) were penicillin-nonsusceptible; PCV7 covered 96.3% of these; PCV10 covered 96.3% and PCV13 covered 100%. The overall incidence of clinical pneumonia and CXR+Pn was 6276/100,000 and 2120/100,000, respectively.

Conclusion

Pneumococcal disease and pneumonia burden is considerable in children in Bogotá, Colombia. Vaccination with pneumococcal conjugate vaccines has the potential to decrease this burden. Epidemiologic data are critical in assessing the potential impact of introduction of PCVs into national immunization schedules.     

HIV-Related High Risk Sexual Behaviors and Practices Among Women in Bogotá, Colombia

ABSTRACT

Determinants associated with high-risk sexual behaviors were investigated in 1,133 sexually active women in Bogotá, Colombia. A self-administered questionnaire was completed by two groups of women: 721 representing the general population (GP), and 412 commercial sex workers (CSWs). High-risk sexual behaviors for HIV/AIDS were evident in both groups. Nevertheless, consistent condom use was reported by only 6% of the GP group, as compared to 67% of the CSWs. Failure to recognize high-risk routes for HIV infection was indicated in 69% of the GP women for anal sex, and by the majority of both groups for intercourse during menses (56% GP women and 54% CSWs). Multivariate analysis revealed that education level, actual age, and age of first sex experience were significant predictors of high-risk sexual practices. The necessity for educational programs regarding high-risk sexual practices and risk of HIV/ AIDS is evident for HIV/AIDS prevention.     

HIV-related high risk sexual behaviors and practices among women in Bogotá, Colombia

Determinants associated with high-risk sexual behaviors were investigated in 1,133 sexually active women in Bogotá, Colombia. A self-administered questionnaire was completed by two groups of women: 721 representing the general population (GP), and 412 commercial sex workers (CSWs). High-risk sexual behaviors for HIV/AIDS were evident in both groups. Nevertheless, consistent condom use was reported by only 6% of the GP group, as compared to 67% of the CSWs. Failure to recognize high-risk routes for HIV infection was indicated in 69% of the GP women for anal sex, and by the majority of both groups for intercourse during menses (56% GP women and 54% CSWs). Multivariate analysis revealed that education level, actual age, and age of first sex experience were significant predictors of high-risk sexual practices. The necessity for educational programs regarding high-risk sexual practices and risk of HIV/ AIDS is evident for HIV/AIDS prevention.     

Cross sectional survey of perpetrators,victims, and witnesses of violence in Bogotá, Colombia

OBJECTIVES: To establish the prevalence and distribution of witnesses, victims, and perpetrators of different types of violence in the general population and the proportion of victims consulting health services or reporting the incident to authorities. METHODS: Cross sectional survey of a random sample of 3007 inhabitants between the ages of 15 and 60 in the city of Bogotá, Colombia, in 1997, based on a face to face interview. RESULTS: Age adjusted past year prevalence of witnesses, victims, and perpetrators of physical aggression was 61%, 27%, and 27%, respectively, while lifetime prevalence of witnesses, victims, and perpetrators of assault with a weapon in this population reached 70%, 55%, and 5.8%. Between 11% and 67% of the victims consulted a health service and less than 32% reported the incident to an authority. Those involved in most types of physical violence tended to be young, male, from lower middle social classes, with some degree of secondary education, and single or divorced. CONCLUSIONS: Prevalence of witnesses and victims of violence in this sample appears to be high, while perpetrators constitute a small proportion. Violence is not equally distributed throughout the population suggesting the possibility of identifying a population at higher risk for the development of intervention programmes.     

Dengue and dengue hemorrhagic fever epidemics in Brazil: what research is needed based on trends, surveillance, and control experiences?

Dengue epidemics account annually for several million cases and deaths worldwide. The high endemic level of dengue fever and its hemorrhagic form correlates to extensive domiciliary infestation by Aedes aegypti and multiple viral serotype human infection. This study analyzed serial case reports registered in Brazil since 1981, describing incidence evolutionary patterns and spatial distribution. Epidemic waves followed the introduction of every serotype (DEN 1 to 3), and reduction in susceptible individuals possibly accounted for decreasing case frequency. An incremental expansion of affected areas and increasing occurrence of dengue fever and its hemorrhagic form with high case fatality were noted in recent years. In contrast, efforts based solely on chemical vector control have been insufficient. Moreover, some evidence demonstrates that educational measures do not permanently modify population habits. Thus, as long as a vaccine is not available, further dengue control depends on potential results from basic interdisciplinary research and intervention evaluation studies, integrating environmental changes, community participation and education, epidemiological and virological surveillance, and strategic technological innovations aimed to stop transmission.     

Provider Barriers and Facilitators to Screening for Intimate Partner Violence in Bogotá, Colombia

We conducted interviews with 27 health care personnel in Bogotá, Colombia, to examine provider barriers and facilitators to screening for intimate partner violence (IPV). We used systematic qualitative analysis to identify the range and consistency of beliefs. We found that respondents did not routinely screen for IPV. Providers listed numerous barriers to screening. Ways to improve screening included increased clinician training, installing systematic IPV screening, providing patient education, and implementing health care setting interventions. Improving the care for IPV survivors will involve translating health care personnel preferred solutions into more systematic IPV screening interventions.     

The 1918-19 influenza pandemic in Boyacá, Colombia

To quantify age-specific excess-mortality rates and transmissibility patterns for the 1918-20 influenza pandemic in Boyacá, Colombia, we reviewed archival mortality records. We identified a severe pandemic wave during October 1918-January1919 associated with 40 excess deaths per 10,000 population. The age profile for excess deaths was W shaped; highest mortality rates were among infants (<5 y of age), followed by elderly persons (>60 y) and young adults (25-29 y). Mean reproduction number was estimated at 1.4-1.7, assuming 3- or 4-day generation intervals. Boyacá, unlike cities in Europe, the United States, or Mexico, experienced neither a herald pandemic wave of deaths early in 1918 nor a recrudescent wave in 1920. In agreement with reports from Mexico, our study found no death-sparing effect for elderly persons in Colombia. We found regional disparities in prior immunity and timing of introduction of the 1918 pandemic virus across populations.     

Provider barriers and facilitators to screening for intimate partner violence in Bogotá, Colombia

We conducted interviews with 27 health care personnel in Bogotá, Colombia, to examine provider barriers and facilitators to screening for intimate partner violence (IPV). We used systematic qualitative analysis to identify the range and consistency of beliefs. We found that respondents did not routinely screen for IPV. Providers listed numerous barriers to screening. Ways to improve screening included increased clinician training, installing systematic IPV screening, providing patient education, and implementing health care setting interventions. Improving the care for IPV survivors will involve translating health care personnel preferred solutions into more systematic IPV screening interventions.     

Dengue epidemic in Belém, Pará, Brazil, 1996-97

We describe clinical and epidemiologic findings during the first epidemic of dengue fever in Belém, Pará State, Brazil, in 1996-97. Of 40,237 serum samples, 17,440 (43%) were positive for dengue by virus isolation or serologic testing. No hemorrhagic cases or deaths were reported. Mycobacterium tuberculosis     

Leisure-time physical activity among women in a neighbourhood in Bogotá, Colombia: prevalence and socio-demographic correlates

This study measured the prevalence of leisure-time physical activity in women from 18 to 69 years of age and identified correlated social factors in the neighborhood of Santafe, Bogotá, Colombia. Levels of physical activity were calculated through a population survey (n = 1,045). Logistic regression modeling identified factors associated with inactivity. Some 79.1% of respondents reported being inactive; 15.7% practiced physical exercise irregularly; and 5.2% regularly practiced physical exercise. After adjustment of covariates, physical inactivity was associated with not participating in recreational weekend activities on Sundays and not planning to lose weight. The results of this study show the high proportion of physically inactive women in a community in Bogotá Intervention strategies should be developed to reinforce recreational weekend activities on promoted by the municipality.     

Results of Global Youth Tobacco Surveys in Public Schools in Bogotá, Colombia

BACKGROUND: The purpose of this paper is to use data from the Global Youth Tobacco Survey (GYTS) conducted in Bogotá, Colombia, in 2001 and 2007 to examine changes in tobacco use among youth 13-15 years of age. The current tobacco control effort in Bogotá will be accessed relative to Colombia ratifying the World Health Organization Framework Convention on Tobacco Control (WHO FCTC) in 2008. METHODS: GYTS was implemented in public schools in Bogotá, Colombia, by the Colombian National Cancer Institute. Data were collected from students in classrooms using self-administered procedures. RESULTS: Between 2001 and 2007, ever having smoked cigarettes decreased along with exposure to secondhand smoke (SHS) at home, having an object with a tobacco logo on it, and having been offered free cigarettes by a tobacco company representative. Prevalence of current cigarette smoking did not change from 2001 to 2007 (32.9% and 29.9%). Exposure to pro-tobacco advertising increased, reaching 71.4%, and 73.4% respectively, in 2007. Having been taught about the harmful effects of tobacco use did not change over time. CONCLUSIONS: The government of Colombia ratified the WHO FCTC in 2008. However, Colombia has one of the highest levels of cigarette smoking among 13-15 year olds in the Region of the Americas. The tobacco control effort in Colombia has much work to do, including recognition that the levels of smoking among adolescents are already as high as those of adults. Future declines in tobacco use among adolescents in Bogotá will likely depend on development of a comprehensive tobacco control program.     

Host selection and parasite infection in Aedes taeniorhynchus,endemic disease vector in the Galápagos Islands

Host selection in blood-sucking arthropods has important evolutionary and ecological implications for the transmission dynamics, distribution and host-specificity of the parasites they transmit. The black salt-marsh mosquito (Aedes taeniorhynchus Wiedemann) is distributed throughout tropical to temperate coastal zones in the Americas, and continental populations are primarily mammalphilic. It is the only indigenous mosquito in the Galápagos Islands, having colonised the archipelago around 200,000 years ago, potentially adapting its host selection, and in the process, altering the dynamics of vector mediated pathogen interactions in the archipelago. Here, we use blood–meal analysis and PCR-based parasite screening approach to determine the blood-feeding patterns of A. taeniorhynchus in the Galápagos Islands and identify potential parasite transmission with which this mosquito could be involved. Our results show that A. taeniorhynchus feeds equally on mammals and reptiles, and only one avian sample was observed in 190 successful PCR amplifications from blood meals. However, we detected endemic filarial worms and Haemoproteus parasites known to infect various Galápagos bird species in mosquito thoraces, suggesting that feeding on birds must occur at low frequency, and that A. taeniorhynchus may play a role in maintaining some avian vector-borne pathogens, although more work is needed to explore this possibility. We also isolated three different DNA sequences corresponding to hemogregarine parasites of the genus Hepatozoon from mosquito and iguana blood samples, suggesting that more than one species of Hepatozoon parasites are present in Galápagos. Phylogenetic analysis of Hepatozoon 18sRNA sequences indicates that A. taeniorhynchus may have facilitated a recent breakdown in host–species association of formerly isolated Hepatozoon spp. infecting the reptile populations in the Galápagos Islands.     

Eco-bio-social determinants of dengue vector breeding: a?multicountry study in urban and periurban Asia

Objective

To study dengue vector breeding patterns under a variety of conditions in public and private spaces; to explore the ecological, biological and social (eco-bio-social) factors involved in vector breeding and viral transmission, and to define the main implications for vector control.

Methods

In each of six Asian cities or periurban areas, a team randomly selected urban clusters for conducting standardized household surveys, neighbourhood background surveys and entomological surveys. They collected information on vector breeding sites, people’s knowledge, attitudes and practices surrounding dengue, and the characteristics of the study areas. All premises were inspected; larval indices were used to quantify vector breeding sites, and pupal counts were used to identify productive water container types and as a proxy measure for adult vector abundance.

Findings

The most productive vector breeding sites were outdoor water containers, particularly if uncovered, beneath shrubbery and unused for at least one week. Peridomestic and intradomestic areas were much more important for pupal production than commercial and public spaces other than schools and religious facilities. A complex but non-significant association was found between water supply and pupal counts, and lack of waste disposal services was associated with higher vector abundance in only one site. Greater knowledge about dengue and its transmission was associated with lower mosquito breeding and production. Vector control measures (mainly larviciding in one site) substantially reduced larval and pupal counts and “pushed” mosquito breeding to alternative containers.

Conclusion

Vector breeding and the production of adult Aedes aegypti are influenced by a complex interplay of factors. Thus, to achieve effective vector management, a public health response beyond routine larviciding or focal spraying is essential.     

Detection of Helicobacter pylori in drinking water treatment plants in Bogotá, Colombia,using cultural and molecular techniques

Helicobacter pylori is one of the most common causes of chronic bacterial infection in humans, and a predisposing factor for peptic ulcer and gastric cancer. The infection has been consistently associated with lack of access to clean water and proper sanitation. H. pylori has been detected in surface water, wastewater and drinking water. However, its ability to survive in an infectious state in the environment is hindered because it rapidly loses its cultivability. The aim of this study was to determine the presence of cultivable and therefore viable H. pylori in influent and effluent water from drinking water treatment plants (DWTP). A total of 310 influent and effluent water samples were collected from three drinking water treatment plants located at Bogotá city, Colombia. Specific detection of H. pylori was achieved by culture, qPCR and FISH techniques. Fifty-six positive H. pylori cultures were obtained from the water samples. Characteristic colonies were covered by the growth of a large number of other bacteria present in the water samples, making isolation difficult to perform. Thus, the mixed cultures were submitted to Fluorescent in situ Hybridization (FISH) and qPCR analysis, followed by sequencing of the amplicons for confirmation. By qPCR, 77 water samples, both from the influent and the effluent, were positive for the presence of H. pylori. The results of our study demonstrate that viable H. pylori cells were present in both, influent and effluent water samples obtained from drinking water treatment plants in Bogotá and provide further evidence that contaminated water may act as a transmission vehicle for H. pylori. Moreover, FISH and qPCR methods result rapid and specific techniques to identify H. pylori from complex environmental samples such as influent water.